1. The Field of the Invention
The present invention relates to orthodontic bracket systems.
2. The Relevant Technology
Orthodontics is a specialized field of dentistry that involves the application of mechanical forces to urge poorly positioned or crooked teeth into correct alignment and orientation. Orthodontic procedures can be used for cosmetic enhancement of teeth, as well as medically necessary movement of teeth to correct underbites or overbites. For example, orthodontic treatment can improve the patient's occlusion and/or enhanced spatial matching of corresponding teeth.
The most common form of orthodontic treatment involves the use of orthodontic brackets and wires, which together are commonly referred to as “braces.” Orthodontic brackets are small slotted bodies configured for direct attachment to the patient's teeth or, alternatively, for attachment to bands which are, in turn, cemented or otherwise secured around the teeth. Once the brackets are affixed to the patient's teeth, such as by means of glue or cement, a curved arch wire is inserted into the bracket slots. The arch wire acts as a template or track to guide movement of the teeth into proper alignment. End sections of the arch wire are typically captured within tiny appliances known as tube brackets or terminal brackets, which are affixed to the patient's bicuspids and/or molars. The remaining brackets typically include open arch wire slots and apply orthodontic forces by means of ligatures attached to the brackets and arch wire (e.g., by means of tie wings on the brackets).
Orthodontic bracket systems are typically either made of metal, ceramic, or plastic. Plastic brackets are less preferred because they tend to stain easily, and are not as strong as the alternative materials. Ceramic brackets are often preferred by patients over metal brackets because they can be formed so as to be transparent or translucent, although they are significantly more expensive. Because of the greater expense associated with ceramic brackets, as a compromise between price and aesthetics, some practitioners and patients will use ceramic brackets on the upper dental arch and metal brackets on the lower dental arch, as the upper arch is more prominent when a patient smiles.
Attempts to mix ceramic and metal brackets on the same arch can result in unintended buccal-lingual movement of the tooth to which the replacement bracket is attached. This is because metal brackets and ceramic brackets are provided with different slot floor thicknesses. Conventional ceramic brackets include thicker slot floor thicknesses to satisfy strength requirements.